helen boyd's journal of gender & trans issues

Tag: biology

This is a great short article on the ambiguities of sex as expressed by humans, mammals, fish and various other creatures, and covers topics like chromosomal variety, embryonic sex determination, and reproductive strategies. It’s a nice Sex 101 – and by that I don’t mean sex as in f*cking, but sex as in male/female. A lot of reasonably smart and educated people seem to think that gender is variable but sex is “natural” and binary when in fact that’s not nearly as true either.

Dean Spade recently wrote a short piece about how we might use language to de-gender bodies. It’s smart and concise – just as you’d expect from Dean Spade.

About Purportedly Gendered Body Parts

I have been thinking about how much I would like it if people, especially health practitioners, exercise instructors and others who talk about bodies a lot, would adjust their language about body parts heavily associated with gender norms. Lots of people who identify as feminists and allies to trans people still use terms like “female-bodied,” “male body parts,” “bio-boy,”and “biologically female.” Even in spaces where people have gained some basic skills around respecting pronoun preferences, suggesting an increasing desire to support gender self determination and release certain expectations related to gender norms, I still hear language used that asserts a belief in constructions of “biological gender.” From my understanding, a central endeavor of feminist, queer, and trans activists has been to dismantle the cultural ideologies, social and legal norms that say that certain body parts determine gender identity and gendered social characteristics and roles. We’ve fought against the idea that the presence of uteruses or ovaries or penises should be understood to determine such things as people’s intelligence, proper parental roles, proper physical appearance, proper gender identity, proper labor roles, proper sexual partners and activities, and capacity to make decisions. We’ve opposed medical and scientific assertions that affirm the purported health of traditional gender roles and activities and pathologize bodies that defy those norms. More→

I’m not going to try to re-phrase this article about how ovaries/testicles are determined by a single gene. Better you read it from the source:

As embryos, our gonads aren’t specific to either gender. Their default course is a female one, but they can be diverted through the action of a gene called SRY that sits on the Y chromosome. SRY activates another gene called Sox9, which sets off a chain reaction of flicked genetic switches. The result is that premature gonads develop into testes. Without SRY or Sox9, you get ovaries instead.

But Henriette Uhlenhaut from the European Molecular Biology Laboratory has found that this story is woefully incomplete. Maleness isn’t just forced onto developing gonads by the actions of SRY – it’s permanently kept at bay by another gene called FOXL2.

Uhlenhaut developed a strain of genetically engineered mice, whose copies of FOXL2 could be deleted with the drug tamoxifen. When she did this, she found that the females’ ovaries turned into testes within just three weeks. The change was a thorough one; the altered organs were testes right down to the structure of their cells and their portfolio of active genes. They developed testosterone-secreting Leydig cells, which pumped out as much of the hormone as their counterparts in XY mice. They only fell short of actually producing sperm.

Uhlenhaut found that FOXL2 and SOX9 are mutually exclusive – when one is active, the other is silent and vice versa. The two genes are at opposite ends of a tug-of-war, with sex as the prize. FOXL2 sticks to a stretch of DNA called TESCO, which controls the activity of Sox9. By sticking to TESCO, FOXL2 keeps Sox9 turned off in the adult ovary. Without its repressive hand, Sox9 switches on and sets about its gender-bending antics.

and

Uhlenhaut’s work isn’t just of academic interest. It could also help to treat disorders of sexual development. It could also change how gender reassignment therapies are done, paving the way for gene therapies rather than multiple painful surgeries.